Sluice for dams



1. CHAPMAN AND w, F. R. HEYNGLDS.

SLUICE FOR DAMS. APPLICATION FILED MAY 6, 1920.

Patented Jan.17,1922.

buen/21776:

UNITED STATES JAMES CHAPMAN AND WILLIAM FREDERICK ROGER REYNOLDS, 0F JOHANNESBURG,

TRANSVAAL PROVINCE, SOUTHl AFRICA.

SLUICE FOR DAMS.

Application filed May 6,

To aZZ. lwhom t may cof/teem:

Be it known that JAMES CHAPMAN and lViLLIAM FREDERICK ROGER RnYNoLDs, British subjects, residing at Twickenham venue, Auckland Park, Johannesburg. and Heaths I-Iotel, Pritchard Street, Johannesburg, rTransvaal Province, of the Union of South Africa, respectively, have invented certain new and useful Improvements in Connection with Sluices for Dams, o't which the following` is a specification.

The present invention has reference to submerged discharge sluices employed for discharging water from an enclosure in which it is confined and more particularly to sluicc valves provided in dams for desilting purposes, or other purposes.

The' invention is illustrated in the accompanying drawing in which- Fig. I is a vertical section ot a masonry dam to which the invention is applied,

Fig. IIV is' sectional partial plan on lli- A., Fig. I.

Fig. III is a vertical seetionot a terroccncrete dam.

Fig. IV is a sectional partial plan on B-B, Fig. III.

Referring to the drawings, l indicates a dam in which are formed sluices 2 which discharge water from the dam below the surface.

neoi` the diiiiculties connected with this kind of sluice is to conduct the water to the bed of the stream 3 `below the dam, without endangering the dam foundation. Hitherto it has been the custom to provide horizontal sluices from which the water issues as massive horizontally directed j ets with considerable destructive potentiality. Since it is usually necessary to place the sluices at some height above the river bed 3, the jets from the sluices are especially liable to destroy the river bed 3 below the dam. It has therefore been customary to protect the toe oi' the dam by an expensive downstream masonry apron doubly curved to conduct the water down to the level o't the river bed Moreover in sluices of this kind Ot which the applicants are aware, the discharging water has been confined in a tunnel formed through the dam; and as the water in the tunnel flows at high velocity due to the head of water in the dam, the result has been to set up vibration dangerous 'to the dam structure.

Specification of Letterslatent.

Patented J an. 17, 1922.

1920. Serial No. 379,334.

A purpose of the present invention is to provide an arrangement for discharging the water from the dam in a safer manner, which permits the downstream masonry apron to be done away with or considerably reduced, and which minimizes vibration due to the iow of water through the dam.

According to the present invention the sluice 2 is so disposed as to direct the water at a downward inclination to the horizontal. From vthe sluice gate 4 the water is discharged as a free jet 5 that is a jet unconlinedby walls or roo'f-Onto an apron 6 which, near to the sluice gate 4, is substanti ally parallel with the liet. Said apron thereafter curves gradually so as to terminate horizontally or nearly so at 7 at the level of the downstream river bed 3, or other desired discharge point. Such a form causes the water to spread laterally and Hatten, and to be delivered at the bed of the stream with the desired direction of flow. The iiattening of the stream is materially assisted by the centrifugal :torce exerted by it in rounding the curve of the apron.

The contour Ot the'apron will depend upon the height oi' the sluice 2 above the toe 7 of the apron and the length of the apron; the curve being made as smooth as possible for any given values of these factors. The sluice being approximately tangential to the upper end ot the apron. its inclination to the horizontal is thus determined. In the eX- amples shown the inclination is about 30 degrees.

In order to avoid vibration set up by water flowing with high velocity through a conning tunnel, and also to obtain structural advantages, the sluice gate is positioned at or about the inner face 8 of the dam wall as illustrated, and the curved apron is formed wholly or partly within the dam. In the construction illustrated in Fig. I the apron 6 constitutes the floor ot a tunnel 9 which at all cross sections is of such height and width as not materially to confine the Outiiowing stream and which widens towards the mouth 10 to permit the stream to flatten and spread laterally. Air ducts l1 may be provided to ensure the maintenance of atmospheric pressure in the tunnel; and buttresses l2 may be built to compensate any reduction of strength or mass in the darn due to the tunnel. As a measure ot precaution in cases where the bed of the river is of such a nature as to be readily eroded, a concrete pavement 13 may be constructed on the river bed 3 in line with the toe 7 of the apron to receive the outiowing water.

The sluice 2 is preferably shaped as a nozzle which is short in relation to its width or diameter and is designed for free discharge under the head of water in the dam. In the drawings said nozzle is shown as provided by a conical or conoidal casting 14C which terminates in the sluice gate casing 4c. The nozzle is preferably such as to form a jet smaller than the sluice gate socket 4. The jet therefore clears said socket whereby vibration due to the water eddying in the,

same is avoided. The sluice gate is operatedy by a hand wheel l5 which in the Fig. I construction projects from the face of the dam. a platform 16 being provided for the operator.

The arrangement of the apron within the dam structure is of special applicability to ferro-concrete dams as shown in Figs. III and IV, since the normal construction of such dams affords ample width for the apro .Ii 6. In such cases the apron can be formed as a continuous transverse girder extending' between the buttresses 17 (Fig. IV), which mechanically strengthens the dam structure.

We claim l. The combination with a dam, of a downwardly inclined discharge sluice in the inner face thereof, and shaped as a tapering nozzle, and an apron onto which said sluice discharges, said apron near the sluice being substantially parallel with the axis of the sluice and curving thence to a substantially horizontal direction.

2. The combination with a `dam, discharge means including a downwardly inclined tapered nozzle, and an apron for receiving the water from the nozzle, said apron being at its head substantially parallel with the nozzle and curving thence to a substantially horizontal direction.

3. The combination with a water retaining structure, of a discharge sluice nozzle inclined to discharge water at a downward inclination and shaped t0 form such water as a jet, a sluice valve arranged adjacent said nozzle, and comprising a casing, said casing being larger than the jet passing through it from the nozzle, and an apron onto which the jet is received, said apron being substantially parallel with the jet next to the sluice valve and curving to a substantially horizontal direction.

4l. The combination with a water retaining structure, of a downwardly inclined discharge sluice, shaped as a nozzle, which is short relatively to its width, and an apron onto which said sluice discharges, said apron near the sluice being substantially kparallel with the axis of the sluice and curving thence to a substantially horizontal direction.

In testimony whereof we aiiix our signatures.

IAMEs CHAPMAN. p WILLIAM FREDERICK RocER REYNOLDS. 

